1. Field of the Invention
The present invention pertains to the art of cooking appliances and, more particularly, to an oven door assembly including an angled glass pane for a cooking appliance.
2. Discussion of the Prior Art
Ovens and their general construction are well known. In general, an oven includes a cooking cavity having an opening which is selectively closed by a door assembly. Usually, ovens are of two general configurations, the ovens are either built-in units, i.e. into a cabinet or wall, or the oven is a free standing range including a cooktop. The doors furnished with ovens can be composed of multiple components which can include a sealing panel, thermal insulation, a window, an intermediate panel, an outer panel, handles, hinges and, in some instances, a decorative face covering made of metal, glass or the like.
One important concern in connection with constructing an oven door is the need to assure that a front or outer surface of the door is maintained at an acceptable level throughout a cooking operation as the front surface can be touched by a consumer. In an oven door which lacks a window or transparent zone used to visually inspect the contents of an oven cavity without opening the oven door, a significant amount of room exists for insulation material. Therefore, under these circumstances, the front surface can be readily prevented from excessively heating.
When a window is provided in the door, the available space for insulation is significantly reduced. Regardless, excessive heating of the front surface of the door must still be considered. In the prior art, this potential problem has been addressed in various ways, such as by providing for a force flow of cooling air through the door or reducing the radiation permeability of the window panes by coating the panes or forming them from thermochromatic materials. Unfortunately, the forced cooling air flow can simply be too costly or complicated to efficiently address this surface temperature concern, and employing either thermochrome or coated panes can negatively affect the visual quality of the window.
U.S. Pat. No. 5,337,727 addresses this problem by arranging one or more angled window panes between inner and outer parallel window panes in a common frame for an oven door. That is, the overall window arrangement must include an inner pane, an outer pane and at least one center pane, with the center pane(s) being at an acute angle to the inner and outer panes. With this construction, heat is conducted into upper or lower parts of the door by reflecting the heat back and forth between adjacent, relatively angled window panes. Therefore, this known prior art provides for the multiple reflections and creates radiation paths between each of the parallel inner and outer panes and the angled center pane(s). Unfortunately, this prior art arrangement is not considered to limit the temperature of the outer surface of an oven door in the most efficient and effective manner.
For at least these reasons, there exists a need in the art for a more effective and economical manner to assure that the front surface of an oven door which includes a window does not overheat during operation of the oven, particularly during high temperature operations such as self-cleaning cycles.